UPDATE 1-Transocean CFO Cauthen to retire

* CFO Greg Cauthen, 51, to retire

* Shares close down 2.74 pct

SAN FRANCISCO, April 7 (Reuters) - Transocean Ltd (RIG.N) said on Tuesday its Chief Financial Officer Greg Cauthen would leave the world's largest offshore drilling contractor by the end of September, depending on when a replacement is found.

A spokesman for the company said Cauthen, 51, had retired for "personal reasons." Transocean recently moved about a dozen senior executives to Switzerland from Houston as part of a reincorporation for tax reasons.

His departure after eight years with Transocean comes less than a week after leading oilfield services company Halliburton Co (HAL.N) announced the early retirement of Cris Gaut, president of drilling and evaluation and a former CFO who had been tipped as a future CEO. [ID:nN01439498]

The company's shares closed down 2.74 percent, or $1.76, at $62.58 on the New York Stock Exchange. (Reporting by Braden Reddall)